Announcing HAProxy 3.4

blog20260602-01.cfg

global
  stats socket /run/haproxy/admin.sock user haproxy group haproxy mode 660 level admin 

defaults mydefaults
  log global
  mode http
  option httplog
  option dontlognull
  timeout connect 10m
  timeout client  10m
  timeout server  10m

frontend mysite
  bind :80
  use_backend %[path,map_beg(virt@paths.map)]
  default_backend webservers
 
backend webservers
  server web1 127.0.0.1:8080

blog20260602-02.bash

# Add a backend named 'test-backend'
echo "add backend test-backend from mydefaults mode http" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# 'New backend registered.'

# Add a server to the backend
echo "add server test-backend/server1 127.0.0.1:3000 check" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# 'New server registered.'

# Enable the server
echo "enable server test-backend/server1" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# Enable health checks
echo "enable health test-backend/server1" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# Publish the backend
echo "publish backend test-backend" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# 'Backend published.'

# Add an entry to the map file
echo "add map virt@paths.map /test test-backend" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# Show map displays entry_cnt
echo "show map" | sudo socat stdio unix-connect:/run/haproxy/admin.sock
# id (file) description
5 (virt@paths.map) pattern loaded from file 'virt@paths.map' used by map at file '/etc/haproxy/hapee-lb.cfg' line 45. curr_ver=0 next_ver=0 entry_cnt=1

blog20260602-03.bash

# Place the server into maintenance mode
echo "set server test-backend/server1 state maint" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# Wait for the server to be removable
# then remove the server
echo "wait 2s srv-removable test-backend/server1; del server test-backend/server1" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# 'Server deleted.'

# Unpublish the backend
echo "unpublish backend test-backend" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# 'Backend unpublished.'

# Wait for the backend to be removable
# then delete the backend
echo "wait 2s be-removable test-backend; del backend test-backend" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# 'Backend deleted.'

# Delete the map file entry
echo "del map virt@paths.map /test" | sudo socat stdio unix-connect:/run/haproxy/admin.sock

# Show map displays entry_cnt
echo "show map" | sudo socat stdio unix-connect:/run/haproxy/admin.sock
# id (file) description
5 (virt@paths.map) pattern loaded from file 'virt@paths.map' used by map at file '/etc/haproxy/hapee-lb.cfg' line 45. curr_ver=0 next_ver=0 entry_cnt=0

blog20260602-04.cfg

frontend mysite
  bind :80
  use_backend webservers
 
# Enable QMux in the backend
backend webservers
  server myserver 127.0.0.1:443 ssl verify none alpn h3,h2

# Enable QMux in the frontend
frontend qmux-fe
  bind :443 ssl crt /etc/haproxy/ssl.pem alpn h3,h2
  http-request return status 200 content-type text/plain string "Hello, qmux!"

blog20260602-05.cfg

backend web_servers
  filter comp-res
  compression algo gzip
  compression type text/css text/html text/javascript application/javascript text/plain text/xml application/json

blog20260602-06.cfg

log-profile syslog
  log-tag "haproxy"
  on close format "$HAPROXY_HTTP_LOG_FMT"
  on http-req format "%[var(req.log_message)]"

frontend mysite
  bind :80
  acl is_evil_client req.hdr(user-agent) -m sub evil
  http-request set-var(req.log_message) str("Blocking evil client") if is_evil_client
  http-request do-log profile syslog
  http-request deny if is_evil_client

blog20260602-07.cfg

global
  cpu-policy performance threads-per-core 1
  cpu-affinity per-core

blog20260602-08.cfg

global
  cpu-affinity per-ccx
  max-threads-per-group 4

blog20260602-09.cfg

healthcheck mycheck
  type httpchk
  http-check connect alpn h2
  http-check send meth HEAD uri /health ver HTTP/2 hdr Host www.example.com
 
backend webservers
  server web1 10.0.0.1:80 check healthcheck mycheck